T-Mobile just sent out invitations for a big launch event happening in NYC on April 21. What might they be up to?

Our money is on the successor to the T-Mobile G1 (also announced in NYC at a T-Mo event), which will almost certainly be the HTC Magic we've seen announced in Europe.

We can also expect that a major Android update will come along with it, since the only place we've seen a soft keyboard, which is necessary for the touchscreen-only Magic, is in the Cupcake development distribution. We'll keep you posted as we know more.